Evaporator unit



Oct. 9, 1945. B. c. JoHNsoN I EVAPORATOR UNIT 2 Sheets-Sheet 1 Fild July 13, 1944 Bernard CfJofinson' B. c; JOHNSON 2,386,613

EVAPORATOR UNIT Filed July 13, 1944' .2 Sheets-Sheet 2 'Qct. 9, 1945';

3 NME U Bernard GJoimsan Patented Oct. 9, 1945 ,U'NlTED STAT ES PATENT OFFICE.

EvAPoRA'roR UNIT Bernard 0. Johnson, Mundelein', Ill., assignor to, Houdaille-Hershey Corporation, Detroit, Mich, a corporation of Michigan Application July 1 3, 1944, Serial No. 544,748

6 Claims.

This invention relates to heat exchanger units having spent fluid conveying ducts equipped with pockets for acting as traps to retain unspent fluid fluid is spent. l

More particularly the invention relates to an evaporator unit wherein refrigerant is first passed through a shelf of the unit and is then in heat exchange relation in the unit until the circulated to a manifold at the bottom of the unit which manifold distributes the refrigerant to a plurality of passageways extending along the bottom and up the sides of the unit to header chambers and wherein these header chambers discharge spent gaseous refrigerant through serpentine ducts extending over the top of the unit and having localized depending pockets along the lengths thereof to trap drops of liquid refrigerant from the spent gaseous refrigerant so that the refrigerant will be completely gasified and its heat absorption capacity fully spent before it is removed from the unit.

This application is a continuation-in-part of my copending application entitled Evaporator unit U. S. Serial 533,546, filed May 1, 1944.

In my copending application Serial No. 533,546

.there is described and claimed an evaporator unit which has a top wall formed from inturned flanges on the sidewalls. Spent refrigerant ducts are embossed in these inturned flanges for conveying exhausted refrigerant from the tops of the headers in the sidewalls of the unit.

- According to the present invention the spent refrigerant ducts leading from the headers in the sidewalls of an evaporator unit over the top of the unit are now equipped with dependin localized pockets to act as traps for any liquid refrigerant that might be entrained in the gaseous These pockets ducts and be discharged with these hen an object of the present invention toziprovide a sheet metal heat exchanger having a top wall equipped with spent refrigerant ducts -containing localized pockets along the lengths A further object of the invention is to provide an evaporator unit with a trap for liquid refrigerant about to leave the unit so that the liquid will be completely gasified before it is discharged from the unit.

A still further object of the invention is to provide an evaporator unit with serpentine spent refrigerant ducts leading from a header of the unit and equipped with depending pockets.

Another object of the invention i to provide a sheet metal evaporator unit having a bottom wall, upstanding sidewalls, inturned flanges on the sidewalls providing a top, header chambers embossed in the sidewalls, refrigerant ducts embossed in the side and bottom walls discharging into the header chambers, spent refrigerant ducts embossed in the inturned flanges for removin refrigerant from the header chambers, a plurality of depending localized pockets embossed in the inturned flanges in communication with the spent refrigerant ducts to receive liquid therefrom, and-a refrigerated shelf supported on the sidewalls and supplying refrigerant to the refrigerant ducts.

Other and further'objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings, which, by way of preferred example only illustrate one embodiment of the invention.

On the drawings:

Figure 1 is a top plan view of an evaporator unit according to this invention illustrating, in dotted lines, pockets in the spent refrigerant ducts.

Figure 2 is a front end elevational view of the unit of Figure 1.

Figure 3 is a fragmentary plan view of a portion of the top wall of the unit of Figures 1 and 2 taken along the line III-III of Figure 2 and illustrating the pockets in several of the spent refrigerant ducts.

Figure 4 is an enlarged fragmentary vertical the sheet metal evaporator unit of this invention. The unit I is composed of embossed, brazed or welded together metal sheets or plates including an inner sheet II and an outer sheet i2. The sheets H and 12 after being secured together are bent so as to provide a bottom Hla, spaced opposed vertical sidewalls llib, Nb, and inturned top flanges lflc, llic cooperating to enclose a sharp freezing chamber C as best shown in Figure 2.

A shelf 13 issecured to the 'sidewalls lb, llib of the unit Hi in spaced relation above the bottom Hla thereof. This shelf I3 is composed of embossed secured together. metal sheets including a top sheet I4 and a bottom sheet i5.

The top sheet l4 of the shelf I 3 has an embossed nipple l6 thereon near the rear end of the unit as best shown in Figures 2 and 5. The bottom sheet l of the shelf has a serpentine embossment i8 thereon leading from the nipple I 6 to a second nipple l9 also formed on the top sheet E4. The nipples l6 and |9 are in transverse alignment near the rear end of the unit and a tube is secured to the nipple IS.

The tube 20 discharges into a manifold duct provided by an embossment 2| on the sheet i2 along the central portion of the bottom We of the unit. As shown in Figures 2 and 6 the tube 20 extends into the duct provided by the embossment 2|.

The outer sheet l2 of the unit l0 has embossments 22 therein which define refrigerant circulating ducts extending transversely outward from the manifold duct provided by the embossment 2|. These embossments 22 extend along the bottom Ilia of the unit and up alongthe sidewalls Nb of the unit in spaced parallel relation to end in transverse enlarged embossments 23, 23 formed in the sidewalls Nib, Nib near the top thereof These embossments 23 are semi-cylindrical and are aligned with similar semi-cylindrical embosse ments 24, 24 on the inner sheet The embossments 23 and 24 cooperate to provide header chambers 25, 25 for the unit.

Embossrnents 26 are formed on the outer sheet I 2 and extend upwardly from near the front ends of the embossments 23 over the tops of the flanges lflc, I00.

Th embossments 26, 26, as best shown in Figure I extend rearwardly along the top of the unit V II into spaced relation from the rear of the unit.

The inner sheet I I of the unit has embossments 21, 21 thereon directly under the embossments 26 and about midway along the lengths of these embossments. The embossments 21 define pockets in the ducts provided by the embossments 26.

The front ends of the embossments 26 mate with embossments 23, 23 on the inner sheet H for defining passages and additional traps which connect the ducts of the embossments 26 with the ducts provided by additional embossments 23, 29 on the outer sheet l2. The embossments 23 are in spaced parallel relation inwardly from the embossments 26 and extend from the rear to the front of the unit about midway between the inner and outer ends of the flanges I00.

' Localized embossments 30 in the inner sheet l| provide pockets for the ducts created by the embossments 29.

. The'front ends of the embossments 29 are aligned with transverse embossments 3| on the inner sheet near the front end of the unit.

These embossments 3| provide connecting ducts and traps to ducts provided by additional embossments 32 formed in the outer sheet [2 near the inner edges of the flanges Hlc, lllc. Embossw ments 33 are formed in the inner sheet I under the mbossments 32 to define traps or pockets for the ducts provided by the embossments 32.

10 end portions 260 and 29a, respectively. These offset portions extend rearwardly beyond the rear ends of the embossments 32 and serve to center the connecting embossments 28 about midway between the inner and outer ends of the flanges lfic.

Brackets 35, 35 are riveted to the inner ends of the flanges llib, Hib at the front and rear ends of theunit to hold these flanges in alignment and to provide a rigid top wall for the unit it.

As shown in Figure 4, th rear ends of the embossments 32 have raised portions such as 3211 to'provide a larger opening for receiving the end of the connecting tube 34 so that the tube can have ample capacity. The raised portion 32a of 25 one of the ducts 32 is directly above an embossment 36 on the inner sheet II. This embossment 36 extends rearwardly and has a, nipple defining portion 36a receiving the end of an exhaust tube '31.

Refrigerant is supplied to the unit through the inlet tube i1 and from this tube the refrigerant flows through the serpentine duct provided by the embossment IS in the shelf l3. From the discharge end of the serpentine duct the refrig- 35 erant flows through the tube 20 into the manifold distributing duct provided by the embossment 2|. Fromthe manifold distributing duct the refrigerant flows along the bottom and sides of the unit through refrigerant distributing ducts pro- 40 vided by the spaced parallel embossments 22.

The refrigerant is discharged from these refrigerant distributing ducts into the header chambers 25 where it is allowed to boil and gaseous or spent refrigerant is discharged from the tops ends of the header chambers 25 near the front end of the unit into the spent refrigerant ducts provided by the embossments 26.

Liquid refrigerant entrained in the spent refrigerant flowing through the ducts of emboss- -ments 26 is trapped in the traps provided by the embossments 21. The refrigerant next flows through the connecting ducts defined by the embossments 23 into other spent refrigerant ducts provided by the embossments 29 and these embossments 23 have pockets provided by embossments 30 for trapping remaining liquid in the spent refrigerant. Connecting ducts provided by the embossments 3| discharge into the innermost spent refrigerant ducts formed by the embossments 32. Pockets provided by embossments 33 serve to trap additional remaining liquid refrigerant.

The connecting ducts provided by the embossments 28 and 3| may also trap off some entrained liquid but the gaseous refrigerant may sweep the liquid through these ducts since the cross sectional area of the connecting ducts is about the same as the cross sectional area of the conveying ducts provided by embossments 26, 29 and 32.

The tube 34 connects one of the innermost duots with the other innermost duct so that all of the spent refrigerant is discharged into the pocket provided by the embossment 36. This pocket of the embossment 36 drains to the spent 7 refrigerant outlet tube 31.

ity has beenexhausted and it turns into a gas for commingling with the gas being discharged.

The unit I canbe readily suspended in a refrigerator cabinet from the top thereof and for this purpose the flanges l0c, I00 are provided with holes 38 at the four comers of the unit to receive suspension bolts or the like structure (not shown). i

The refrigerant inlet tube I1 is closed with a cap Ila. Likewise the exhaust tube 31 is closed with a cap 31a. These caps l'la and 31a are used in shipping for sealing the interior of the unit.

The inner sheet ll along the 'bottomwall Illa of the unit has a raised embossment 39 extending transversely across the rear end of the unit as shown in Figures 2 and 6. This embossment 39 serves as a tray stop for ice trays mounted on the bottom of the unit. As shown in Figures 2 and 5 the nipples l5 and I9 extend upwardly from the shelf [3 near the rear end of the unit and the inlet tube I! as well as the connecting tube have upstanding ver- 3 top of the unit to define spent refrigerant ducts, and said inner sheets having localized embossments communicating with spaced portions of the spent refrigerant ducts to trap liquid in the refrigerant flowing therethrough.

2. A sheet metal evaporator unit having opposed side walls with header chambers therein, inturned flanges on the upper ends of the side walls providing a top for the unit, embossments on said flanges providing sepentine spent refrigerant ducts communicating with the tops of the headers, a spent refrigerating tube communicating with said ducts, and localized pockets at spaced intervals along the lengths of the ducts for trapping liquid refrigerant entrained with the spent refrigerant.

3. In a sheet metal evaporator unit having a bottom, sides, inturned flanges on the sides cooperating to form a top, and spent refrigerant ducts embossed in said flanges, the improvement of localized embossments in said flanges communicating with said spent refrigerant ducts at spaced intervals along the lengths thereof to trap liquid entrained with the spent refrigerant.

4. An evaporator unit comprising secured to- A gether contiguous metal sheets embossed to provide refrigerant circulating ducts, header chambers, and spent refrigerant removal ducts, said sheets being bent to form the bottom, sides and tical legs secured in these nipples. The nipples.

and upstanding legs of the tube also act as tray stops for ice trays mounted on the shelf l3.

From the above description it will be understood that the invention now provides a sheet metal heat exchanger or evaporator unit which utilizes all of the capacity of a fluid flowing therethrough by retaining the fluid until it is completely spent. In evaporator units employing volatile liquid refrigerants, the refrigerant is of necessity retained in the unit in heat exchange relationship. with the shar freezing space de-' fined by the unit until it is completely gasified. Serpentine spent refrigerant ducts are equipped with traps to receive any droplets of liquid refrigerant entrained in the spent gases and to re? tain these droplets until they are completely Easified. v

It will, of course. be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims. l

I claim as my invention: 1. An evaporator unit comprising contiguo secured-together metal sheets bent to form the bottom, side walls and top of a sharp freezing chamber, embossments in said sheets formin header chambers in each side wall of the unit together with refrigerant circulating ducts around top of a sharp freezing chamber with aheader chamber in each side and with refrigerant circulating ducts extending around the bottom and sides to discharge into the header chambers, said sheets being further embossed to define spent refrigerant ducts extending from the tops of the header chambers over the top of the unit, and additional embossments in the top of the unit in one of said sheets forming localized pockets to refrigerant ducts.

5. A sheet metal evaporator unit comprising inner and outer secured-together contiguous metal sheets bent to form the bottom, side walls and top of a sharp freezing chamber, said outer sheets having embossments therein defining a header chamber at the upper end of each side wall together with U-shaped refrigerant circulating ducts extending around the bottom and side walls and terminating at their upper ends in said header chamber, said'outer sheet being further embossed to define an inlet manifold communipockets for said spent refrigerant circulating ducts to trap liquid materialentrained in the,

spent refrigerant.

6. A sheet metal evaporator unit comprising contiguous secured-together metal sheets bent to the bottom and side walls of the unit dischargingat their upper ends into the header chambers and an inlet duct communicating with the bottom portions of the circulating ducts to supply refrigerant r said outer sheet having embossments therein extending from the tops of the header chamber defining embossments over the form a bottom wall, upstanding side walls and inturned flanges extending from the upper ends of the side walls, said inturned flanges being in closely spaced aligned relationship-to form a top for the unit, embossments in said flanges defining spent refrigerant circulating chambers, and additional embossments in said flanges defining depended localized wells for said ducts to trap liquid entrained with the spent refrigerant.

' BERNARD C. JOHNSON. 

